Commit 56ed4f6c authored by Matt Woodrow's avatar Matt Woodrow
Browse files

Bug 1730682 - Flatten opacity before setting up clips. r=miko 

Pushing the clip for the opacity item into the clip manager has a non-trivial cost, so we get better performance if we handle flattening the item before that.

Differential Revision: https://phabricator.services.mozilla.com/D125633
parent a8494d48

gfx/layers/wr/WebRenderCommandBuilder.cpp

+31 −0
Original line number Diff line number Diff line
@@ -1728,6 +1728,37 @@ void WebRenderCommandBuilder::CreateWebRenderCommandsFromDisplayList( 


    DisplayItemType itemType = item->GetType();



    // If this is a new (not retained/reused) item, then we need to disable

    // the display item cache for descendants, since it's possible that some of

    // them got cached with a flattened opacity values., which may no longer be

    // applied.

    Maybe<AutoDisplayItemCacheSuppressor> cacheSuppressor;



    if (itemType == DisplayItemType::TYPE_OPACITY) {

      nsDisplayOpacity* opacity = static_cast<nsDisplayOpacity*>(item);



      if (!opacity->IsReused()) {

        cacheSuppressor.emplace(aBuilder.GetDisplayItemCache());

      }



      if (opacity->CanApplyOpacityToChildren(

              mManager->GetRenderRootStateManager()->LayerManager(),

              aDisplayListBuilder, aBuilder.GetInheritedOpacity())) {

        // If all our children support handling the opacity directly, then push

        // the opacity and clip onto the builder and skip creating a stacking

        // context.

        float oldOpacity = aBuilder.GetInheritedOpacity();

        aBuilder.SetInheritedOpacity(oldOpacity * opacity->GetOpacity());



        CreateWebRenderCommandsFromDisplayList(opacity->GetChildren(), item,

                                               aDisplayListBuilder, aSc,

                                               aBuilder, aResources, false);



        aBuilder.SetInheritedOpacity(oldOpacity);

        continue;

      }

    }



    // If this is an unscrolled background color item, in the root display list

    // for the parent process, consider doing opaque checks.

    if (XRE_IsParentProcess() && !aWrappingItem &&

layout/painting/nsDisplayList.cpp

+0 −24
Original line number Diff line number Diff line
@@ -4984,30 +4984,6 @@ bool nsDisplayOpacity::CreateWebRenderCommands( 
    wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,

    const StackingContextHelper& aSc, RenderRootStateManager* aManager,

    nsDisplayListBuilder* aDisplayListBuilder) {

  // If this is a new (not retained/reused) item, then we need to disable

  // the display item cache for descendants, since it's possible that some of

  // them got cached with a flattened opacity values., which may no longer be

  // applied.

  Maybe<AutoDisplayItemCacheSuppressor> cacheSuppressor;

  if (!IsReused()) {

    cacheSuppressor.emplace(aBuilder.GetDisplayItemCache());

  }



  if (CanApplyOpacityToChildren(aManager->LayerManager(), aDisplayListBuilder,

                                aBuilder.GetInheritedOpacity())) {

    // If all our children support handling the opacity directly, then push

    // the opacity and clip onto the builder and skip creating a stacking

    // context.

    float oldOpacity = aBuilder.GetInheritedOpacity();

    aBuilder.SetInheritedOpacity(oldOpacity * mOpacity);



    aManager->CommandBuilder().CreateWebRenderCommandsFromDisplayList(

        &mList, this, aDisplayListBuilder, aSc, aBuilder, aResources, false);



    aBuilder.SetInheritedOpacity(oldOpacity);

    return true;

  }



  MOZ_ASSERT(mChildOpacityState != ChildOpacityState::Applied);

  float oldOpacity = aBuilder.GetInheritedOpacity();

  aBuilder.SetInheritedOpacity(1.0f);